Transfer tape is becoming increasingly common in the manufacture of business forms or the like. For example U.S. Pat. No. 5,129,682 (the disclosure of which is hereby incorporated by reference herein) shows a business form having removable labels associated therewith which is constructed by applying a piece of transfer tape to the back of paper stock, and then die cutting labels from the area covered by the transfer tape. There are many circumstances in which it is desirable to provide a self-imaging liner associated with transfer tape, for example in the manufacture of business forms such as shown in U.S. Pat. No. 5,129,682, or in the construction of other types of labels. The self-imaging liner allows the user to see what was printed on a label made with the transfer tape, providing a record copy.
According to a first aspect of the present invention, a transfer tape is provided with a self-imaging liner. The transfer tape comprises: A carbonless, self-contained primary sheet having first and second faces. A first polyethylene coating or film layer of about 1 mil thick, or less, on the first face. A first silicone coating over the first polyethylene coating or film layer. A pressure sensitive adhesive coating on the first silicone coating. A second polyethylene coating or film layer of about 1 mil thick, or less, on the second face. And a second silicone coating over the second polyethylene coating. Typically the second polyethylene coating is applied on the second face of the carbonless sheet. The transfer tape may consist of the primary sheet, first and second polyethylene coatings or film layers, first and second silicone coatings, and pressure sensitive adhesive, or a CB coating may be provided on the second silicone coating. The CB coating allows an image printed on the transfer tape to also transfer to a CF coated sheet positioned beneath the transfer tape.
The transfer tape may be provided in a roll configuration with the adhesive engaging the second silicone coating when in the spiral roll. A wide variety of different types of materials and weights of material may be provided, applied in different manners. However it is necessary that the polyethylene be provided as a coating and not as a film, and preferably it is sprayed on (or the equivalent). The silicone coating is typically provided at a weight of about 3-10 grams per square meter, with five gm./m.sup.3 being approximately optimum, and typically is a differential coating of silicone. That is the silicone has a first side having a stronger affinity for adhesive than a second side, and the second side of the differential coating is what is engages the pressure sensitive adhesive. The pressure sensitive adhesive may typically be applied as a hot melt adhesive, or from a pre-wound tape.
The invention also comprises a business form comprising a face stock and a transfer tape, the transfer tape pressure sensitive adhesive engaging the face stock. The transfer tape which engages the face stock is as described above. Labels may be die cut out of the face stock, and matrix material removed, as in U.S. Pat. No. 5,129,682. A CF sheet may be provided underneath the transfer tape if a CB coating is provided on the second silicone coating of the transfer tape.
According to another aspect of the invention a method of making a transfer tape from a carbonless, self-contained primary sheet having first and second faces is provided. The method comprises the steps of: (a) Spraying a first polyethylene coating, or applying a polyethylene film layer, of about 1 mil thick, or less, on the first face. (b) Applying a first silicone coating over the first polyethylene coating. (c) Applying a pressure sensitive adhesive coating on the first silicone coating. (d) Spraying a second polyethylene coating, or applying a film layer, of about 1 mil thick, or less, on the second face. And, (e) applying a second silicone coating over the second polyethylene coating. There is also the further step of winding the transfer tape into a roll configuration with the pressure sensitive adhesive engaging the second silicone coating. Finally there is the optional further step of applying a CB coating over the second silicone coating.
It is the primary object of the present invention to provide a transfer tape having a self-imaging ply that is constructed in a simple straight-forward manner, and can be utilized in the construction of a business form with labels. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.